“DNI Clapper explained his response in the letter to Chairman [Dianne] Feinstein [(D., Calif.)] and apologized for the misunderstanding,” said Michael Birmingham, spokesperson for the Office of the Director of National Intelligence.

Clapper “values the decades-long stellar relationship he has with Congress and remains focused on leading the intelligence community,” Birmingham told the Free Beacon in a statement Monday.

Clapper disclosed in a June 21 letter to Feinstein that his answer to questions about the electronic surveillance were “erroneous” during March 2013 testimony before the Senate Select Committee on Intelligence.

Clapper has been DNI since August 2010. Prior to that he was undersecretary of defense for intelligence in the George W. Bush administration. He also headed the National Geospatial Intelligence Agency from 2001 to 2006.

His tenure as DNI has been marked by several misstatements, such as the comment before the House Intelligence Committee in February 2011 that Egypt’s Islamist Muslim Brotherhood was “largely secular.”

Clapper also misspoke during a Senate Armed Services Committee hearing in March 2011. During the hearing, he undermined public Obama administration efforts against Libya’s leader Muammar Gaddafi during the civil war in Libya by predicting that Gaddafi would “prevail” in the conflict. The dictator was killed and his body dragged through the streets in October 2011.

The United States’ top intelligence official also appeared uninformed during a December 2010 television interview when he did not know that 12 terrorists had been arrested in the United Kingdom for plotting attacks earlier in the day.

However, his comments during the March 12 Senate hearing revealed that he misled the Congress on the widespread NSA surveillance. Sen. Ron Wyden (D., Ore.) had asked Clapper at the hearing for a yes or no answer on whether NSA collects data on “millions or hundreds of millions of Americans.”

“Not wittingly. There are cases where they could inadvertently perhaps collect but not wittingly,” Clapper said.

That answer was exposed as false by recent disclosures of documents made public by former NSA contractor Edward Snowden. Snowden, an NSA systems administrator, revealed NSA’s clandestine PRISM computer system that is used to gather telephone metadata – phone numbers and calls between numbers and the duration of the calls – on some 150 million Americans. The program is part of NSA’s search for terrorists and spies.

Clapper said in his letter, “my response was clearly erroneous – for which I apologize.”

Clapper explained in the letter that he was “faced with the challenge of trying to give an unclassified answer about our intelligence collection activities, many of which are classified.”

Clapper said he mistakenly answered questions about more restricted eavesdropping on actual telephone conversations under Foreign Intelligence Surveillance Act authorities.

Clapper said did not realize that Wyden was asking about Section 215 of the USA Patriot Act that expanded government authority to obtain Americans’ personal records in the hunt for “international terrorism or clandestine intelligence activities.”

The PRISM program gathers data under the Patriot Act power.

Clapper said his staff acknowledged the error at the time of the hearing but he was only now openly correcting the record because the metadata spying program was recently declassified.

Clapper, a former Defense Intelligence Agency director, said he has testified before Congress “dozens” of times and that he “takes all such appearances seriously and prepare[s] rigorously for them.”

“But mistakes will happen, and when I make one, I correct it,” he said.

A spokesman for Feinstein declined to say whether the senator believes Clapper should resign over the misstatement.

“I have received Director Clapper’s letter and believe it speaks for itself,” Feinstein said in a statement. “I have no further comment at this time.”

“Sen. Wyden is deeply troubled by a number of misleading statements senior officials have made about domestic surveillance in the past several years,” Caiazza said in a statement. “He will continue pushing for an open and honest debate about programs and laws that touch on the personal lives of ordinary Americans.”

Caiazza said the senator’s staff contacted Clapper’s office in March on the inaccurate statement on the bulk collection of data on Americans.

“The ODNI acknowledged that the statement was inaccurate but refused to correct the public record when given the opportunity,” he added.

A spokeswoman for Rep. Mike Rogers (R., Mich.), chairman of the House Permanent Select Committee on Intelligence, said Rogers was traveling on Monday and was unavailable for comment.

“Admitting to a lie is tantamount to resignation,” Codevilla said. “No one can be expected to repose confidence on any official who lies, especially not one whose word must be routinely accepted in lieu of revelation of secrets.”

Former U.S. Ambassador to the United Nations John Bolton agreed.

“Clapper’s long, drawn-out, utterly inadequate performance in response to Sen. Wyden’s question has shredded his credibility and the public’s confidence in his grasp of his job,” said Bolton, who also served as undersecretary of state for international security and arms control. “Time for him to go.”

Former House Intelligence Committee Chairman Pete Hoekstra (R., Mich.), who retired from Congress in 2011, said Clapper should be given a pass on the NSA misstatement.

“I have always found Jim Clapper to be forthright with Congress,” Hoekstra said. “If this is an isolated event and he still has the confidence of the Senate Intelligence Committee, he should stay as DNI.”